Is this even possible?

D

DavCardei

New member
Hi all, first post here.

Okay, here it is....
(This may have been asked or talked about somewhere, but searching for it under my own verbage returned no usable data.)

We all know about the line skipping=aliasing problem. My question is...IF the HDMI out to an external screen is showing the ACTUAL live image at any given moment, is it showing us the images prior to being RECORDED in the h.264 codec?

And if so, is it possible to virtualy eliminate aliasing by recording the SCREEN image externally to avi or mov file?

I am new to this and have no camera to experiment with as of yet. I also admit that this could possilby, to certain people who know much more than me, be a rather dumb question. So be it.

Thanks for any and ALL input!

Dav
 
well the line skipping is how you go from 18mp to 1080p... since the hdmi is outputting (i believe) 1080p while it is in standby, no, it won't bypass the line skipping. It may, however, bypass the h.264 compression...
 
Nathan, thanks for a quick response.

I'm thinking that if you COULD record externally, you could choose the recording codec or file type you prefer by using the camera's HDMI output.
IOW, the camera is just "idling" through the scene and recording is external to a device that can record at the maximum resolution available from the sensor. Said device would have much more processing power that would allow full use of sensor res. This, I presume, would depend on if the shutter is rolling when placed in video mode to begin with(which it seems it would have to be) and not just when recording in camera. Again, really just recording the "live view" image externally at full resolution.

I hope I've made sense.
 
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Yes it does make sense.

First, the mechanical shutter is not in use while recording video, it is locked in the up position, out of the way of the sensor. The "shutter" in video mode is all electronic. So, in theory, what you are proposing should work. You MAY get a better quality (uncompressed?) image recorded on the external recorder.... but I have a feeling the h.264 is encoded before it is sent out the hdmi port.
 
This has been talked about for forever, and is how people tap the HDMI and SDI ports of video cameras. The problem is that the HDMI port on these cameras are not displaying a clean output. It has things like shutter and aperture information on it, and other stuff.

It's just not usable, or people would have been doing this long ago.
 
For every engineering problem there are as many answers as there are GOOD engineers.
Write a program for the external compensation of that issue and keep the rest. Any interested software engineer could do this easily.

EVEN IF the resulting solution to the "problem" costs $2000.00, how much less is the total solution to people who have already invested their future in the use of these cameras? Last I checked the Red One was still $17,500 before glass.

Just a thought.
 
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If I remember my 7D correctly I believe there is a way to get rid of all the overlays to where the image is covering the entire screen. I believe the only problem with that though is when a face appears it tries to put the face recognition box (or whatever you call it) around the individuals face and track them. If that were to be bypassed with a firmware hack then I can't see why one couldn't record that image via HDMI (before compression).
 
You are right Ian-T,

It all comes down to pathway manipulation via firmware internally, and software externally.

Anyone else have a thought?

Thanks,
Dav
 
I don't think the t2i has any face recognition, and I believe by pressing the display button a few times, the overlays are removed. (at least on the internal lcd)
 
Nathan.Buxton said:
I don't think the t2i has any face recognition, and I believe by pressing the display button a few times, the overlays are removed. (at least on the internal lcd)
Click to expand...

No, they are not. The box stays there. NONE of the Canon cameras gives a clean screen via the HDMI output.
 
On the 7d, and also on the 5d i believe, when you press the info button you can remove all data from the camera LCD screen as well as on the HDMI output EXCEPT the white BOX for ZOOM in BUT it will disappear when REC button is pressed BUT and a RED REC Dot is left on the upper right.

So, yeah I guess Perrone is partly right, the BOX stays when no recording is done.
 
Thanks for the input Ted.

Does the software that comes with the camera for recording onto your pc require the record button on the camera to be pressed? Just trying to figure whether the external software would have to produce a virtual shutter.

Dav
 
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